Can the Action some concentration spells grant be used in Attacks of Opportunity with the War Caster feat?

Can the Action some concentration spells grant be used in Attacks of Opportunity with the War Caster feat?

For a specific example, Dragon Breath and Sunbeam both have actions to do damage after being cast. Could that action be used in that circumstance?

Buying A Magic Item Downtime Activity – Opportunity to purchase later

I’m DM’ing using the downtime activity rules in Xanathar’s Guide to Everything and I was wondering if there are any rules (or suggested approaches) to allowing my players to purchase one of their discovered magic items at a later date.

For instance, one of the players rolled for a Saddle of the Cavalier but none of the party has a horse. Do the rules allow the player to track down the merchant at a later date to buy the item? Or is this more of a DM’s discretionary decision?

Do these spell-like abilities, from the prestige class Holy Vindicator, provoke opportunity attacks?

The prestige class Holy Vindicator (in the Advanced Player’s Guide) has three spell like abilities.

Divine Wrath and Divine Retribution (which can be triggered by a done or received critical hit) and Divine Judgement (which can be triggered by bringing a creature to -1 or less hit points with a melee attack)

Do all of these abilities provoke an opportunity attack (assuming that the attacked creature is in the conditions to strike one) since they’re all spell-like abilities?

Can I make an Opportunity Attack during Time Stop?

Time Stop indicates that the caster has 1d4+1 rounds to do whatever they want and that time does not pass for other creatures. Presumably everyone is effectively barred from using their Reactions, but this is not expressly stated. Furthermore, it suggests that the caster could simply walk away from a character they are engaged in melee without using the Disengage action, but that is also not expressly stated by the spell.

Other spells and effects that remove Reactions specifically state as such. Such as Shocking Grasp:

On a hit, the target takes 1d8 lightning damage, and it can’t take reactions until the start of its next turn.

…Monk’s Open Hand Technique:

It can’t take reactions until the end of your next turn.

…or the Gibbering Mouther’s Gibbering ability:

On a failure, the creature can’t take reactions until the start of its next turn and rolls a d8 to determine what it does during its turn.

The exclusion of similar language within Time Stop is notable, so can the caster of Time Stop trigger Opportunity Attacks during the course of their Actions that others character may use Reactions to capitalize upon?

Can an attack of opportunity be made against a net if the restrained creature is being moved?

A creature, other than the one restrained by the net, can make an attack against the net (AC 10) which by dealing at least 5 slashing damage will free the restrained creature.

If a player restrained by a net – who is adjacent to another player – is grappled by some creature and carried away, could the adjacent player make an attack of opportunity against the net, thus ending the restrained condition?

How can one make multiple opportunity attacks during one round?

The title is pretty straight-forward. By default, players can make only one opportunity attack per round, since it uses their reaction of which they only have one.

Which features, spells etc. exist that allow a player to make multiple opportunity attacks during one round? These attacks don’t necessarily have to be able to occur during the same turn (nor do they have to be able to occur on different turns).

Do I have to take the Ready action to make an opportunity attack?

So, a friend and I are in a debate right now about how an opportunity attack works.

From what I understand after reading the handbook, you can only perform an opportunity attack if you use an action to ready a reaction first.

So, for example, I can’t use an opportunity attack without using an action to ready a reaction before simply by the fact that an enemy got out of my melee range, meaning that if I want to make an opportunity attack at one point, I should spend my action not attacking any enemy, and then readying a reaction, which in this case is an opportunity attack.

Am I thinking too far? Can I use an opportunity attack just by seeing an enemy getting out of my melee range?

Can a Creature with Multiattack use it on an Opportunity Attack?

I am familiar with both concepts in D&D 5E — an opportunity attack allows the creature to take one reaction to make an attack; a multiattack allows monsters with the ability to take a number of attacks specified in the description on a single attack action.

But does multiattack apply to opportunity attacks taken on a reaction, or do you just use one of the creature’s attacks?

My group is split on this. I think they are able to apply multiattacks, but some of my players disagreed, and frankly, I can see an argument for either way.

Can a Hydra make multiple opportunity attacks at once?

A normal creature only has one reaction that may be used as a single attack of opportunity. A Hydra, though, has one of these reactions per head.

My question would be: may several reactions be combined in reaction to the same action and thus allowing several attacks of opportunity at once?

Scenario: Fighter A attacks Hydra with five heads and then tries to leave, thus provoking an opportunity attack. Now, as a reaction to this, may the Hydra attack Fighter A only once or up to five times?